'round here, building specs call for 40lbs/sf load baring on 1st floors.
Thats 1280 lbs on a 4x8 area. Basically, you're building a floor. Assuming
that your supports are on the 4' ends, you have an 8' span. You will need
2x6 "floor joists" to support that span.

But you did not ask about the support, you asked about the decking. The
thing that particle board hsa going for it is that it's flat and relatively
smooth. It has good compressive stregth but just about no tensile strength.
It makes a good subtrate for counters, and it's relatively cheap. Plywood is
much stronger, but not pretty. The appropriate thickness of your surface
material is going to be driven by the distance between "joists", the
material used, and the acceptable "springyness" of the surface.

We need a little bit more info to give an appropriate reccomendation.

This *may* help

http://www.woodbin.com/calcs/sagulator.htm



"The Pistoleer" wrote in message
...
I will be setting up a bunch of heavy duty steel shelving units with full
size 4' x 8' shelves. The decking can be any 4' x 8' material (full
sheets). I'll be storing a max distributed load of 1200 lbs per shelf.
What's the best material to use as decking. Local Home Depot and Lowes
have
available (5/8" to 3/4" thick) particle board (with or without melamite),
MDF, various varieties of plywood, etc. Dry environment, there will be
two
or three supports between the beams. Particle board seems to be the
standard, but is it the best choice?

Pete
http://www.Pistoleer.com Retail & Wholesale (PH/FX 618-288-4588)
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